Whether it's a question about specifications, code regulations, product usage or installation, the 1-800-NATIONAL Construction Services hotline offers help from these experts:

Mark Chapman, ASTM

Mark, team leader within the 1-800-NATIONAL Construction Services Department, came from our research center where he spent years developing and testing National Gypsum construction systems. As a research engineer, he has extensive knowledge in the structural, fire and sound characteristics of our products and hands-on experience in both residential and commercial construction. With four decades of construction expertise, Mark also has an in-depth understanding of plaster products and their applications.

Jim Farrell

Jim brings over 30 years of construction experience to our 1-800 NATIONAL team, serving as a project manager and GC/owner's representative in various residential and commercial projects, including Class A commercial high and mid-rise construction, healthcare facilities, mixed-use facilities, single-family residential, multifamily and senior living communities. His knowledge brings extensive planning, pre-construction, design, construction and project completion experience to the team. Jim has a degree in Structural Design and Construction Engineering/Construction Management and Electrical Engineering.

Sam Halverson

Sam brings to the 1-800 NATIONAL team more than 20 years of architectural experience developing projects from conception through their final construction for numerous commercial, educational and institutional clients. He has extensive experience related to project schedules, budgets, drawings, permits, bids and specifications. Sam is a member of the systems testing team and the creator of multiple highly-regarded technical resources such as The PURPLE Book®, The SoundBook® and The Wood Book™. He has a Bachelor of Architecture Degree from UNC Charlotte.